Then in 1976, the then military head of state, Murtala Mohammed was assassinated, and Mr Obasanjo took over the reins of power.

As military ruler of Nigeria from 1976-79, General Obasanjo is well-remembered for having eventually handed over to an elected civilian government.

Mr Obasanjo retired to his farm in Otta, in his home state of Ogun, to rear pigs and chickens.

He subsequently became a strong opponent of military rule during the time of General Sani Abacha in the mid-1990s, and was imprisoned in 1995 on coup-plotting charges.

When General Abdulsalami Abubakar took over as head of state following the unexpected death of General Abacha, he released nine key political prisoners, including Mr Obasanjo in June 1998.

On his release from jail, Mr Obasanjo was seen by the northern military power elite, which still retains a strong influence over Nigerian politics, as an ideal candidate for the presidency in the forthcoming civilian elections.

Being a former military man, he understood how to control the army and provide for their needs; and as a southern Christian, he could allay southern fears of political domination by the north.

After some initial reluctance, Mr Obasanjo was persuaded to contest for the presidency in 1999.

No democracy dividend

There was a great deal of optimism at the start of his presidency, that democracy would bring an end to the economic decline and virulent corruption that were the hallmarks of 16 years of unbroken military rule.

But few in Nigeria would argue that at the end of his current term of office, either of these issues has been successfully addressed.

Ethnic and religious violence have increased under Obasanjo

Despite the broad remit and the occasional show-case investigation by the anti-corruption commission, it has so far led to the conviction of just one minor public official.

As for the economy, despite Nigeria's continued massive oil revenues, it is still in very poor shape.

Unemployment remains desperately high, the agricultural sector has been decimated over the years, and an estimated 70% of its population live below the United Nations-defined poverty line.

Instability and human rights

But perhaps of most concern during Mr Obasanjo's tenure has been the high level of communal and religious conflict across the country.

It is estimated that well over 10,000 people have lost their lives since 1999.

The causes of these sporadic outbreaks of violence have been varied, but almost everywhere have pitted Muslim and Christian communities against one another.

These clashes have been far worse than any communal conflicts witnessed during the military era, and led to concerns that political forces have been at work inciting much of the violence.

Whilst hard to quantify this, there is little doubt that competition for political power at the local level has led to the stirring up of latent ethnic and religious tensions.

Concerns have also been expressed over Mr Obasanjo's human rights record.

During his time in office, the army has been accused by human rights groups of two separate massacres (the first in Odi in 1999, the second in Benue State in 2001), in which hundreds of unarmed civilians were killed by soldiers in reprisal for the abduction and killing by local militia groups of security personnel.

Mr Obasanjo has never fully explained these actions, nor have investigations by the military led to the arrest or even public criticism of the army commanders who led the assaults.

Ultimately, Nigerian elections had little to do with satisfying the demands of the estimated 60 million potential voters, and everything to do with securing the backing of those who wield real political and business power behind the scenes, and who can ultimately secure the popular vote for the candidate of their choice.

Mr Obasanjo seemed to have done enough to maintain this support.

He now faces a huge task ahead, if he is to reunite a country that elections have revealed as more divided than ever.